The present invention relates to a system and method for testing a battery to determine if it is a rechargeable battery. More specifically, the present invention relates to an automatic battery detection system and method for use with a wireless telecommunications device having a wireless transceiver powered by a battery. The wireless telecommunications device is placed in an associated charging cradle to test the battery. This testing is performed by a controller in the charging cradle that determines if the battery includes a rechargeable cell and, if it does, if the rechargeable cell needs to be recharged.
Generally, wireless transceivers, such as those used in radios, cell phones, pagers, etc., are powered by rechargeable batteries. Most commercially available rechargeable cells, such as Nickel Metal Hydride (NiMH) or Nickel-Cadmium (NiCd) cells, are recharged by an external charger (i.e., the user removes the batteries from the device and recharges them in the external charger). However, some devices recharge the batteries without removing them from the device.
To recharge the battery without removing it from the device, the type of cell within the battery must first be determined by the device. Usually, the rechargeable batteries are modified to facilitate cell-type detection. This modification of the battery typically is done by adding a third terminal to the battery where detection is performed by a detector that measures the batteries characteristics through an electrical contact with the third terminal.
Another method of in-unit cell detection is performed through some form of user input such as a mechanical switch with an arrow that is lined up with one or more markings on the device. These markings represent chemical symbols or words that indicate the cell-type of the battery to the device charging the cell.
When recharging a battery though a charging cradle it is necessary to first test the battery to reduce the possibility of damaging either the device or the battery. If a device having a non-rechargeable battery is placed in the charging cradle during a recharging operation both the battery and the device could be damaged. Further, if a rechargeable battery is recharged when it is already almost fully charged, the number of charging cycles is lowered and the lifetime of the battery is drastically reduced.